Light diffuser system

ABSTRACT

A light diffuser system suspended from a ceiling below a light source includes a framework of T-bar members depending from the ceiling and defining rectangular openings. Secured in each opening is a one-piece, translucent plastic light diffuser panel, formed in a coffer configuration with the cavity opening downward and the walls of the coffer inclined slightly from vertical toward the center of the opening. The walls are tapered from the bottom to the transverse portion, and are painted with an opaque color coating on the ceiling-facing surface. Light diffusing through the translucent, transverse portion stikes the walls, illuminating the color coating more strongly as the taper of the walls increases, and causing a color gradient effect which enhances the apparent depth of the coffer and increases the esthetic appeal of the diffuser system.

United States Patent 1191 Schwartz [4 1 Nov. 25, 1975 [5 LIGHT DIFFUSERSYSTEM Primary ExaminerRonald .1. Stem [76] Inventor: Robert A. D.Schwartz, 513 Amman! E'mmmer conmd l Independent Road. Oakland, Calif;Attorney, Agent. or Firm-Harris Zimmerman 221 Filed: Apr. 25, 1973 [57]ABSTRACT [21] Apl. No: 354,348 A light diffuser system suspended from aceiling below a light source 1ncludes a framework of T-bar members 1depending from the ceiling and defining rectangular [52] US. Cl 350/319;240/106 R; 350/259 openings. Secured in each opening is a one-piece,[51] Int. Cl. G02B 5/00; F21V 5/00 translucent plastic light diffuserpanel, formed in a [58] Field of Search 350/319, 259, 168; cofferconfiguration with the cavity opening down- 0/l86 108 5 10 ward and thewalls of the coffer inclined slightly from A vertical toward the centerof the opening. The walls [56] References Cited are tapered from thebottom to the transverse portion. UNITED STATES PATENTS and are paintedwith an opaque color coating on the 3.104.834 9/1963 Lipscomb 350/319ceillng'facing Surface- Light diffusing 509,668 5/I97O Omnger et aL240/51. R translucent, transverse portion stlkes the walls, 111um1-3,760,178 9/1973 Miller 240/106 R Hating the Color coating more Stronglyas h taper 0f D173,157 10/1954 .the walls increases, and causing a colorgradient effect D2l2.442 10/1968 Keller, Jr. D48/16 which enhances theapparent depth of the coffer and increases the esthetic appeal of thediffuser system.

13 Claims, 5 Drawing Figures U.S. Patent Nov. 25, 1975 FIG 3.

LIGHT DIFFUSER SYSTEM BACKGROUND OF THE INVENTION Light diffusingsystems suspended from a ceiling have been used to distributeillumination from ceiling mounted fluorescent or similar lamps. Oftenthese systems have employed translucent planar panels to form acontinuous, flat diffusing surface extending over large portions of aceiling. These monotonous expanses of illuminated panel have oftencontributed to an oppressive, non-productive room environment which isfurther exacerbated by the glare produced by such a system. The lampfixtures and suspending structure have often cast shadows on thediffusing panels, which serve not to alleviate the monotony of thediffuser surface but to cause non-uniform illumination of the room, andconfusing multiple shadows on work areas. Attempts to overcome theseproblems by introducing new systems which recess the diffusing panels oremploy secondary diffusers have resulted in a proliferation of parts tobe assembled during installation of each new system. The correspondingincrease in man-hours required for complete assembly has resulted inhigher costs without overcoming'all of the defects of the prior art.

SUMMARY OF THE INVENTION The present invention is directed toward alight diffusing system which overcomes the problems of the prior art andprovides a textured ceiling which is a source of non-glaringillumination and is pleasing to the eye. It comprises a multiplicity ofrectangular or square panels, each formed in a coffer configurationdefined by a lateral translucent portion supported by upwardly extendingwalls which terminate at their lower extremities in horizontallyextending flanges. A framework of T-bar members defining square openingswhich is suspended from the ceiling supports the panels with the flangesresting on the T-bars and the coffer cavities opening downward. Theupwardly extending walls are tapered in thickness from the flange to thelateral portion, and are painted on their ceiling-facing side with anopaque color coating. Light from ceiling-mounted lamp fixtures diffusesthrough the lateral translucent portion of each panel, providingillumination to the area below and also illuminating the walls of thecoffer. The taper of the walls causes them to reflect more lights fromthe upper portions than from the lower, so that the color reflected fromthe walls of each panel has ,an intensity gradient which enhances thedepth effect of the coffer. The coffer configuration removes most of thelateral diffusing surfaces from direct view, greatly relieving the glareand brightness of the ceiling. Furthermore, the enhanced depth effect ofthe coffer panels and the color of the walls of the coffers provides apleasant visual interest which is lacking in prior lightdiffusersystems. Because each panel is a molded single unit, installation issimple and economical, and maintenance of the lamp fixtures is easilyfacilitated. The panels may be used in luminous bays interspersed withacoustical tile or other suspended ceiling material, or they may beemployed as a complete suspended ceiling.

THE DRAWING FIG. 1 is a perspective view of the present invention asseen from above.

FIG. 2 is a perspective view of the present invention as seen frombelow.

2 FIG. 3 is a sectioned side view of the present invention.

FIG. 4 is an exploded sectioned side view of a portion of a lightdiffusing panel.

FIG. 5 is a view similar to FIG. 4 illustrating a modified form of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT area below. It should be notedthat the framework may be formed with openings of various standard sizeswith the panels dimensioned to' match, thus providing a selection ofpanel sizes to suit a wide variety of situations.

Each light diffusing panel is formed by molding translucent whiteacrylic plastic, plexiglass or the like into a single unit with a squarecoffer configuration, as shown in cross-section in FIG. 3. The panel 1 1includes a horizontal flange 12 formed about the perimeter of the paneland resting on the horizontal portion 9 of the framework on all sides ofthe panel. Upwardly directed walls 13, which are inclined inwardly fromvertical toward the center of the panel, support a laterally extendingplanar portion or top wall 14, and define a coffer cavity 20therebetween which opens downward. Walls 13 are joined to the flanges 12by a shoulder 15. All of the vertices are rounded to prevent stressconcentrations.

Because each light diffusing panel is of unitary construction, it may beappreciated that installation is quick and economical. Each panel islifted through its opening diagonally, turned and properly oriented, andset in place. No screws or bolts or other fasteners are required.

As shown in FIG. 4, each of the walls 13 is tapered in thickness fromthe base 16 to the top 17. The ceiling facing surface of the walls ispainted or otherwise coated with an opaque pigmented coating 19. Thecoating blocks all light from the lamps above, so that the onlyillumination of the walls 13 comes from the light diffusing through thewhite, translucent portion 14. Because each wall is tapered inthickness, the incident light from 14 is reflected more strongly by thepigmented coating 19 at the top 17 of the wall, and is more dispersedand less intense at the thicker bottom 16 of the wall. Thus the colorreflected from the wall has a gradient of decreasing intensity from thetop to the bottom of the wall. This gradient serves to enhance theperceived depth of the cavity 20 and make the panels 11 more visuallyinteresting and esthetically pleasing. The panels of the presentinvention may be arrayed in luminous bays interspersed with acousticalceiling tile or the like, or may be extended over an entire ceiling, asshown in FIG. 2. It may be appreciated that due to the cofferconfiguration of the panels 11, the lateral, light-diffusing portions 14are only partially visible at most from below, thus reducing glare andbrightness while delivering optimum illumination. The luminous portions14 set off in the coffer cavity by the colored 3 walls 13 and the darkframe of the framework 7 provide a striking and effective, yeteconomical light diffusing system.

It should be noted that the taper of the walls l3 may be inverted; i.e.,thicker at the top portion 17 and thinner at the lower extremity 16,thereby inverting the intensity gradient and creating another strikingyet pleasing visual effect. Also, it will be appreciated that instead ofpainting or otherwise laminating an opaque coating or layer on the outersurfaces of walls 13, the same general effect could be obtained byplacing an opaque collar or sleeve over the walls.

A modified form of invention is disclosed in'FlG. in which the walls 13are not provided with their outer opaque layer or coating. Instead, anacoustical ceiling is readily provided by coating or spraying aconventional acoustical material on the inner surface of walls 13 toform a layer 21. Such layer may be formed of any suitable open cellsound absorbing material, such as polyurethane foam, sprayed flockingand the like.

With this latter arrangement, light will only pass through thehorizontal translucent wall portion 14, with the remainder of the cofferbearing the sound absorbing material.

As a further feature of the invention, it has been found that the colorprovided in the coating 19, described in the first described embodiment,has a substantial effect in providing novel harmonized lighting in aroom. In other words, by selecting various colors for the coating, thecolor temperature of the room can be readily modified. For example, byproviding a coating possessing an amber color, blue light will beabsorbed.

It should also be understood that in order to optimize this coloreffect, the walls 13, which define an included obtuse angle with topwall 14, should be offset from the vertical by from about l0 to about35, and preferably about 15 as shown in the drawing. This gives anincluded angle of about 105. Too great an angle will result in mostlight passing through the top wall and completely missing the side wallsand entering the room directly.

I claim:

1. Light diffusing means for a ceiling with a light source abovecomprising: a unitary member having side walls joined to a laterallyextending top planar wall and defining a downwardly directed cavity,said top planar wall being translucent for the passage of light from thelight source therethrough, and said side walls being translucent; andopaque means substantially completely covering at least one of theinside and outside surfacesvof all said side walls for preventingpassage of light through said side walls and reflecting incident lightpassing through said top wall.

2. The light diffusing means of claim 1 in which said opaque means isaffixed to the inner surface of said side walls and constitutes a soundabsorbing material.

3. The light diffusing means of claim 1 in which said side walls and topwall define a coffer, and in which said side walls converge towards saidtop wall.

4. The light diffusing system of claim 1, in which the outer surfaces ofsaid side walls are provided with said opaque means as a film to reflectincident light passing through said top wall.

5. The system of claim 4 in which said film comprises a pigmented paintapplied to said surfaces.

6. The system of claim 1 in which said side walls are tapered inthickness from said top wall to the distal ends of said side walls.

7. The system of claim 6 in which said side walls have a minimumthickness adjacent said top wall.

8. The system of claim 1 wherein said member includes horizontallyextending flanges extending outwardly from the distal end portions ofsaid side walls.

9. The system of claim 1 wherein said opaque means is provided with acolor.

10. The system of claim 4 wherein said opaque means is provided with acolor.

11. The system of claim 1 wherein said side walls define included obtuseangles with said top wall.

12. The system of claim 11 in which said obtuse angles are in the rangeof about to 125 13. The system of claim 11 wherein said angles are about

1. Light diffusing means for a ceiling with a light source above comprising: a unitary member having side walls joined to a laterally extending top planar wall and defining a downwardly directed cavity, said top planar wall being translucent for the passage of light from the light source therethrough, and said side walls being translucent; and opaque means substantially completely covering at least one of the inside and outside surfaces of all said side walls for preventing passage of light through said side walls and reflecting incident light passing through said top wall.
 2. The light diffusing means of claim 1 in which said opaque means is affixed to the inner surface of said side walls and constitutes a sound absorbing material.
 3. The light diffusing means of claim 1 in which said side walls and top wall define a coffer, and in which said side walls converge towards said top wall.
 4. The light diffusing system of claim 1, in which the outer surfaces of said side walls are provided with said opaque means as a film to reflect incident light passing through said top wall.
 5. The system of claim 4 in which said film comprises a pigmented paint applied to said surfaces.
 6. The system of claim 1 in which said side walls are tapered in thickness from said top wall to the distal ends of said side walls.
 7. The system of claim 6 in which said side walls have a minimum thickness adjacent said top wall.
 8. The system of claim 1 wherein said member includes horizontally extending flanges extending outwardly from the distal end portions of said side walls.
 9. The system of claim 1 wherein said opaque means is provided with a color.
 10. The system of claim 4 wherein said Opaque means is provided with a color.
 11. The system of claim 1 wherein said side walls define included obtuse angles with said top wall.
 12. The system of claim 11 in which said obtuse angles are in the range of about 100* to 125 *.
 13. The system of claim 11 wherein said angles are about 105 *. 